"A nixie tube is an electronic device for displaying numerals or other information. The glass tube contains a wire-mesh anode and multiple cathodes. IThe cathodes are shaped like numerals. Applying power to one cathode surrounds it with an orange glow discharge. The tube is filled with a gas at low pressure, usually mostly neon and often a little mercury and/or argon, in a Penning mixture."
From "
Wikipedia Nixie Tube".
There are several online sites that deal with Nixie tubes. The most complete as "
NixieClock.de", where is possible to find the valves or even buy kits. That in the figure, of my property, was created using the kit "
Nixie Clock Kit V1.08A" and using Nixie tubes IN-14.
Here is the manual for the assembly, in PDF format and extremely detailed. This watch takes the clock from the 50Hz mains, or you can use an additional receiver module DCF77.
"
Historical Achievements" and "
Clocks Gallery".